The present invention relates to audio video processing and particularly to systems for converting full motion video into a slide show presentation with synchronised sound through the use of content based video reformatting.
Effective use of storage media and/or channel capacity has been the aim of many systems. Management of video data is particularly important because video requires a medium or channel with high capacity, typically many megabytes of data per minute. One way to reduce the medium or channel capacity is by converting a full motion video into a slide show presentation showing salient visuals with corresponding audio rather than full motion video, Known arrangements for conversion of video to slides require manual selection of frames from the video and consequential compiling of a slide presentation. This is a very labor intensive task and therefore impractical to perform on a large scale.
A video is also a pre-packaged presentation which has a fixed pace. This fixed pace is a limitation and is particularly problematic when videos are used in the education context. This is because it assumes that the absorption rate of each member of the target audience is the same. A slide presentation, on the other hand, provides a higher level of inter activity in the sense that the user has the option to view any one slide for a longer or shorter time period, as required. A further advantage of a slide show presentation is that it can easily be augmented with supplementary information, thereby adding further value to the content.
More recently, image-processing techniques have been developed to operate on digital video in order to facilitate the previously manual task of selecting certain frames from a video and compiling a slide presentation. One technique used in such systems is to extract and display only key frames or R-frames from a video. Key frames are frames denoting important events which can serve as an abstract of a video sequence. R-frames are frames representative of a group of frames in a video sequence.
However, such a technique results in from that are considered too closely paced in time and hence do not result in a smooth slide presentation. Further, such an arrangement does not satisfy the channel capacity requirement, because it does not take into account the information content of a frame relative to that directly preceding it and therefore includes redundant frames. For instance, when a scene is relatively static for a couple of moments, this technique would send (or store) successive frames containing little to no further information.
It is an object of the present invention to substantially overcome, or at least ameliorate, one or more of the deficiencies of the above mentioned arrangements.
In accordance with one aspect of the present invention there is provided a method for converting full motion video into a slide show with synchronised audio, said method comprising he steps of:
(a) receiving audio-video data;
(b) separating said audio-video data into an audio stream and a video sequence;
(c) dividing said video sequence into video, each of said video segments comprising a group of frames;
(d) for each said video segment
(d1) extracting at least one representative frame from the corresponding said group of frames;
(d2) calculating a significance measure using said frames;
(d3) using said significance measure, selecting at least one slide frame from said group of frames;
(e) synchronising said audio stream and said slide frames; and
(f) synchronously reproducing said slide frames and said audio stream.
In accordance with another aspect of the present invention there is provided a method for creating a database for use in converting full motion video into a slide show with synchronised audio, said method comprising the steps of:
(a) receiving audio-video data;
(b) separating said audio-video data into an audio stream and a video sequence;
(c) dividing said video sequence into video, each of said video segments comprising a group of frames;
(d) for each said video segment
(d1) extracting at least one repretative frame from the corresponding said group of frames;
(d2) calculating a significance measure using said frames; and
(e) storing at least an identifier to each of said segments, said significance measures and an identifier to said audio stream.
In accordance with yet another aspect of the present invention there is provided a method for displaying a slide show with synchronised audio, said method comprising the steps of:
(f) retrieving at least an identifier to each of a plurality of video segments, significance measures and an identifier to an audio stream, wherein each of said video segments comprising a group of frames;
(g) for each said video segment, using said significance measures, selecting at least one slide frame from said group of frames;
(h) synchronising said audio stream and said slide frames; and
(i) synchronously reproducing said slide frames and said audio stream.
In accordance with yet another aspect of the present invention there is provided apparatus for creating a database for use in converting full motion video into a slide show with synchronised audio, said apparatus comprising:
input means for receiving audio-video data;
audio extraction means for separating said audio-video data into an audio stream and a video sequence;
video dividing means for dividing said video sequence into video segments, each said video segment comprising a group of frames;
key frame extraction means for extracting , for each said video segment, at least one representative frame from the corresponding group of frames of each of said video segments;
significance calculation means for calculating significance measure using said frames;
database storage means for storing said database, the database including at least an identifier to each of said segments, said significance measures and an identifier to said audio stream.
In accordance with yet another aspect of the present invention there is provided apparatus for presenting a slide show with synchronised audio, said apparatus comprising:
presentation retrieval means for retrieving a audio stream and slide frames from said storage means; and
output means for synchronously reproducing said slide frames and said audio stream.
In accordance with yet another aspect of the present invention there is provided a computer program product including a computer readable medium incorporating a computer program for creating a database for use in converting full motion video into a slide show with synchronised audio, said computer program product comprising:
input means for receiving audio-video data;
audio extraction means for separating said audio-video data into an audio stream and a video sequence;
video dividing means for dividing said video sequence into video segments, each said video segment comprising a group of frames;
key frame extraction means for extracting, for each said video segment, at least one representative frame from the corresponding group of frames of each of said video segments;
significance calculation means for calculating significance measures using said frames;
database storage means for storing sad database, the database including at least an identifier to each of said segments, said significance measures and an identifier to said audio stream.
In accordance with yet another aspect of the present invention there is provided a computer program product including a computer readable medium incorporating a computer program for displaying a slide show with synchronised audio, said computer program product comprising:
database retrieval means for retrieving a database, the database including at least an identifier to each of a plurality of video segments, significance measures and an identifier to an audio stream, wherein each of said video segments comprising a group of frames;
selection means for selecting, for each of said video segments, at least one slide frame from said group of frames using said significance measures; and
synchronisation means for synchronising said audio stream and said slide frames; and
output means for synchronously reproducing said slide frames and said audio stream.
In accordance with yet another aspect of the present invention there is provided a computer program product including a computer readable medium incorporating a computer program for converting full motion video into a slide show with synchronised audio, said computer program product comprising:
means for receiving audio-video data,
means for separating said audio-video data into an audio stream and a video sequence;
means for dividing said video sequence into video, each of said video segments comprising a group of frames;
means for processing each said video segment by
(1) extracting at least one representative frame from the corresponding said group of frames;
(2) calculating a significance measure us said frames;
(3) using said significance measure, selecting at least one slide frame from said group of frames;
means for synchronising said audio stream and said slide frames; and
means for synchronously reproducing said slide frames and said audio stream.
In accordance with yet another aspect of the present invention there is provided a computer program product including a computer rile medium incorporating a computer program for creating a database for use in converting full motion video into a slide show with synchronised audio, said computer program product comprising:
means for receiving audio-video data;
means for separating said audio-video data into an audio stream and a video sequence;
means for dividing said video sequence into video, each of said video segments comprising a group of frames;
means for processing each said video segment by
(1) extracting at least one representative frame from the corresponding said group of frames;
(2) calculating a significance measure using said frames; and
means for storing at least an identifier to each of said segments, said significance measure and an identifier to said audio stream.
In accordance with yet another aspect of the present invention there is provided a computer program product including a computer readable medium incorporating a computer program for displaying a slide show with synchronised audio, said computer program product comprising:
means for retrieving at least an identifier to each of a plurality of video segments, significance measures and an identifier to an audio stream, wherein each of said video segments comprising a group of frames;
means for processing each said video segment, using said significance measures, selecting at least one slide frame from said group of frames;
means for synchronising said audio stream and said slide frames; and
means for synchronously reproducing said slide frames and said audio stream.